Integrated circuits have been pivotal to accelerating progress in electronic device performance, enabling device sizes to shrink without sacrificing performance. Integrated circuits have been widely adopted for electronic devices, as opposed to designs using discrete transistors, due to various capabilities that are enabled by the integrated circuits. For example, integrated circuits can be readily mass produced, generally exhibit excellent reliability, and enable a building-block approach to circuit design.
Integrated circuits generally include a semiconductor substrate including a device, such as a transistor, disposed therein. In fact, modern integrated circuits may contain millions of transistors disposed therein. Layers of dielectric materials are formed over the semiconductor substrates and may include additional devices embedded therein (such as DRAM devices). During fabrication of the integrated circuits, electrical connections to the transistors and the additional devices that are embedded in the integrated circuit are generally formed for purposes of completing electrical routing in the circuit. The electrical connections between the devices in the integrated circuit are formed in the layers of dielectric materials through known techniques of selective etching through the layers of dielectric material to form vias that uncover a contact surface of the transistors and additional devices, followed by filling the vias with electrically-conductive material to form the electrical connections. Under some circumstances, configuration of the transistors and additional devices may be such that a direct path through the layers of dielectric materials for via formation is presented for transistors or additional devices that are at different levels within the integrated circuit. While it would be desirable to etch vias to the contact surfaces of the transistors or additional devices that are at different levels, the contact surfaces that are to be uncovered by the respective vias typically lie on different, parallel planes within the integrated circuit. Because etching generally proceeds at constant rates for via formation, “via punch-through” often occurs at shallower contact surfaces, especially when the shallower contact surfaces include a surface of a thin metal-containing layer. “Via punch-through” refers to propagation of the via completely through the thin metal-containing layer. Via punch-through results in ineffective electrical connection upon subsequent filling of the vias with electrically-conductive material, and may compromise the integrity of the integrated circuit by etching through layers that are unintended to be etched.
Accordingly, it is desirable to provide integrated circuits and methods of forming integrated circuits that enable electrical connection to different devices within the integrated circuit while avoiding via punch-through. In addition, it is desirable to provide integrated circuits and methods of forming integrated circuits that avoid via punch-through without compromising insulation of the electrical connections from each other. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.